Explain the continuum of drug use.
please:)

[120 total points] (public health) in one of the largest human experiments ever conducted, in 1954 a randomized controlled trial was run to see whether a vaccine developed by a doctor named jonas salk was effective in preventing paralytic polio. a total of 401,974 children (ages 6–9), chosen to be representative of those who might be susceptible to the disease, were randomized to two groups: 200,745 children (the control group c) were injected with a harmless saline solution (a placebo) and the other 201,229 children (the treatment group t) were injected with salk’s vaccine. what was the point of giving saline solution to the children who didn’t get the vaccine? explain briefly.

Mary has spontaneously decide to make a meal for friends. she is beginning to prepare fin fish and realizes she wants to also prepare a hearty dish ready to serve at the same time. what should she prepare? a: rice which take 20 minutes b: past which takes 15 minutesc: baked potatoes, which take 50 minutes. d: grilled garlic bread, which takes 5 minutes. e: boiled dumplings, which takes 17 minutes.

How could you find out if that advice is based in scientific evidence?